Date post: | 31-Dec-2015 |
Category: |
Documents |
Upload: | earl-hardy |
View: | 227 times |
Download: | 5 times |
CHAPTER 1: THE PHYSICS TOOL KITSections 1.1 and 1.2
The Physics Tool Kit: Ch1, Sections 1 and 2
Objectives
Explain the need for standardization of measurement.
Use the metric and English systems of measurement.
Introduction
The physics student must be able to: Analyze a problem Choose a correct concept formula Manipulate an equation
This chapter gives the basic tools for a physics student. Math techniques Significant digits Accuracy and precision Problem solving strategy
1.1 Standards of Measure
Standard of measure – sets units of measurement for length, weight, and other quantities defined in a way that is useful to a large number of people.
Some interesting historical measurement standards. http://
en.wikipedia.org/wiki/Pottle
Chain – 100 links used for surveying = 66 ft
Rod – 16 men lined up foot to foot; now standardized to 16 1/2 feet
Yard – tip of king’s nose to fingertips of outstretched hand.
Foot – rod divided by 16; was also common to use length of one’s own foot.
Inch – was the length of three barely corns.
US system, sometime called English system, of measurements is a combination of Anglo-Saxon, Roman, and French-Norman weights and measures.
In 1790’s, a decimal system based on the metric system was developed in France Many nations began adopting as official
measurement system. By 1970, the US was the only non-metric
industrialized nation.
Lost in Space http://www.cnn.com/TECH/space/9909/30/mars.metric/
Many businesses, industry and government agencies in the US have now converted voluntarily to the metric system.
In many industries, you – the student and worker – will need to know and use both.
1.2 Introduction to the Metric System SI System of measurement is based
on metric system Gabriel Mouton (1618-1694) System is based on factors of 10
Units are made bigger or smaller by using SI prefixes
SI Base Units
Basic Unit SI Abbreviation Quantity Measured
meter m length
kilogram kg mass
second s time
ampere A electric current
Kelvin K temperature
candela cd light intensity
mole mol amount
SI Derived Units
Derived Unit Abbreviation Quantity Measured
liter L of l volume
cubic meter m3 volume
square meter m2 area
Newton N force
meter per second m/s speed
Joule J energy
watt W power
SI PrefixesMultiple Power of 10 Prefix Prefix
Symbol
1 000 000 000 000
1012 tera T
1 000 000 000 109 giga G
1 000 000 106 mega M
1000 103 kilo k
100 102 hecto h
10 101 deka da
1 100 (base) -
0.1 10-1 deci d
0.01 10-2 centi c
0.001 10-3 milli m
0.000 001 10-6 micro
0.000 000 001 10-9 nano
0.000 000 000 001
10-12 pico p
System Length Time Mass Force & Weight
English foot (ft) second (s)
slug pound (lb)
SI meter (m)
second (s)
kilogram (kg)
Newton (N)
1 lb = 16 ounces (oz) 1 kg weighs 9.80 N or 2.2 lb
1 lb = 4.45 N 1 slug weighs 32.2 lb
1 kg = 1000 g 1 slug = 14.59 kg
Comparison of English and SI Units
Weight and Mass Conversions